1. Field of the Invention
This invention relates to frameless, heated wiper assemblies and systems utilizing such assemblies.
2. Background Art
Referring to FIG. 4, wintery driving conditions cause snow and ice to build up on windshields and wiper assemblies. This buildup of snow and ice deteriorates the performance of the wiper system to properly clear the windshield. As a result, the operator's visibility is reduced. In an attempt to clear the windshield the operator typically activates the vehicle's defroster system in conjunction with the wiper system. As the snow and ice begin to melt, some of the resulting liquid contacts and refreezes to the wiper assembly and sides of the windshield. Wind combined with the relative motion of the vehicle increases this refreezing effect. As this cycle continues, more and more ice buildup occurs on the wiper assembly and windshield resulting in further reduced wiper system performance and operator visibility. This condition continues to worsen to such a point that the wiper system is rendered useless, thereby creating an extremely dangerous driving situation due to greatly reduced operator visibility.
Currently, the only way to solve this problem is for the operator to manually remove the snow and ice from the wiper blade assembly. This is accomplished after the operator pulls off the road or stops at a stop light. Once stopped, the operator can roll down the window, reach his or her arm around the windshield, and snap the wiper against the windshield in an attempt to clear the snow and ice from the wiper blade assembly. However, once the vehicle is back in motion the icing condition quickly returns, making this is a very ineffective and potentially hazardous solution.
There are a few heated wiper blade assemblies that have been patented and claim to prevent ice and snow from accumulating on the wiper assembly and/or the windshield. Examples of such assemblies are disclosed in the following U.S. patents:
U.S. Pat. No. 5,632,058 discloses a heated wiper assembly including exterior heating elements on blade holders and interior elements embedded in the wiper blades;
U.S. Pat. No. 5,504,965 discloses an electrically heated wiper blade utilizing a spiral coiled resistor wire;
U.S. Pat. No. 4,497,083 discloses the use of resistance heating wires disposed along the length of wiper arms, blades and blade carriers;
U.S. Pat. No. 4,325,160 discloses a windshield wiper blade assembly;
U.S. Pat. No. 2,627,011 discloses a heated wiper/squeegee and frame;
U.S. Pat. No. 6,754,933 discloses radiating heat to a wiper arm structure;
U.S. Pat. No. 6,591,443 discloses heater elements in the blade back and flexible blade body of a wiper;
U.S. Pat. No. 6,236,019 discloses a heated windshield wiper assembly;
U.S. Pat. No. 5,603,856 discloses a heated wiper frame;
U.S. Pat. No. 5,558,792 discloses heater elements in a wiper blade back and blade body;
U.S. Pat. No. 5,488,752 discloses a heat conducting apparatus for wiper blades;
U.S. Pat. No. 5,412,177 discloses a heated wiper blade cover;
U.S. Pat. No. 4,152,808 discloses a heating unit of a windshield wiper;
U.S. Pat. No. 5,325,561 discloses a heated wiper blade assembly in which the wiper linkage, as well as the blade and blade retainer, are heated;
U.S. Pat. No. 4,928,344 discloses an electrically heated wiper blade utilizing a fibrous carbon heating element;
U.S. Pat. No. 4,928,345 discloses a heated wiper blade and blade holder;
U.S. Pat. No. 4,967,437 discloses a heated wiper blade assembly;
U.S. Pat. No. 4,387,290 discloses a heater that extends along a wiper blade and its support;
U.S. Pat. No. 4,194,261 discloses a heated wiper arrangement; and
U.S. Pat. No. 6,779,222 discloses a windshield wiper heating device removably attached to a windshield wiper.
These heated wipers come in many different forms and designs. They heat the wiper frame, arm, and blade or combination of these elements by means of heating an element or some other type of added assembly. These types of wipers are somewhat effective in their own way, but are inconvenient to the manufacturer and end user. They are either very costly to manufacture, thereby resulting in a high cost product that is passed through to the consumer, or they are very complex to install, thereby eliminating many of the “do-it-yourself” consumers. They also fail to mention that wipers should work with the windshield defrosting system and act as one. Without the windshield defroster system, the windshield will only freeze up with the accumulating snow and ice, creating a hazardous situation.
In summary, some of the major disadvantages of the prior art, heated wiper assemblies include cost and the complexity for the everyday “do-it-yourself” consumer. Many do not list the operating range of the wiper, or the heat it will produce. It cannot be assumed that they operate at 12 volts or higher. Most, if not all, vehicles have an operating electrical system of 13.5 to 14.5 volts when in operation. Also, vehicle speed is an important fact to the operation of these wipers.